1. Field of the Invention
The present invention relates to an exhaust structure for an engine, and, more particularly, to an exhaust structure for an engine wherein an exhaust line, through which exhaust gas discharged from the engine, has a double pipe structure to prevent condensed water, formed in the exhaust line, from entering the engine, so that it is possible to achieve an enhancement in the durability and reliability of the engine.
2. Description of the Related Art
In general, cogeneration systems are adapted to generate both electricity and heat from a single energy source.
Such a cogeneration system can recover heat of exhaust gas or waste heat of cooling water generated from an engine or turbine during an electricity generation operation, so that the cogeneration system can achieve an increase in energy efficiency of 70 to 80% over other systems. By virtue of such an advantage, the cogeneration system has recently been highlighted as an electricity and heat supply source for buildings. In particular, the cogeneration system exhibits highly-efficient energy utilization in that the recovered waste heat is mainly used to heat/cool a confined space and to heat water.
FIG. 1 is a schematic view illustrating an exhaust structure for an engine included in a conventional cogeneration system.
As shown in FIG. 1, the exhaust structure, which is included in the conventional cogeneration system to outwardly discharge exhaust gas generated from an engine 2, includes an exhaust gas discharge line 4 connected to the engine 2, and adapted to outwardly guide exhaust gas discharged from the engine 2, and a muffler 10 arranged in the exhaust gas discharge line 4 at a level higher than the engine 2, and adapted to reduce noise of the exhaust gas.
The muffler 10 includes a muffler body 16 having an inlet 12 and an outlet 14, through which the exhaust gas discharged from the engine 2 passes, and a condensed water outlet 18 formed at the bottom of the muffler body 16 to outwardly discharge condensed water formed in the muffler body 16.
The exhaust gas inlet 12 and exhaust gas outlet 14 communicate with the exhaust gas discharge line 4.
A plug 20 is mounted to the condensed water outlet 18, in order to open or close the condensed water outlet 18.
Hereinafter, operation of the exhaust structure having the above-mentioned configuration will be described.
When the engine 2 operates, high-temperature exhaust gas is discharged from the engine 2. The exhaust gas is then outwardly discharged via the exhaust gas discharge line 4 and muffler body 16.
At this time, condensed water is generated in the muffler body 16 and exhaust gas discharge line 4 due to a temperature difference between the high-temperature exhaust gas and the atmosphere.
Such condensed water is accumulated in accordance with continued operation of the engine 2. Accordingly, it is necessary to periodically outwardly discharge the accumulated condensed water by opening the condensed water outlet 18.
In the above-mentioned conventional exhaust structure, however, it is impossible to remove condensed water generated in the exhaust gas discharge line 4. For this reason, there is a problem in which the condensed water may flow backward into the engine 2, thereby causing a failure of the engine 2.